GWD-2-Question 12:

bewithjessie

"only by enough to provide them with a comfortable living"

That means if elderly parents' comfortable living conditions are below the comfortable line just to 200$,their children will supplement the income of 200$,meanwhile goverment increase the pension to 20%,thus the same parents' comfortable living condition require only 180$ to the the comfortable line,their children will supplement the income of 180$,not 200$.